共查询到18条相似文献,搜索用时 140 毫秒
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时域电场、磁场和混合场积分方程已被广泛用来分析散射体的时域散射响应.基于适当的空间积分方法和隐式的时间步进算(MOT)法在求解时域磁场和混合场积分方程时总是稳定的,然而在求解TDEFIE时则是不稳定的.在本文中,时域电场积分方程的非奇异性积分采用标准的高斯求积法来计算;而利用参数坐标变换和极坐标变换将其奇异性积分转换成为可以分区域精确快速计算的非奇异性积分.通过数值实验表明,利用该方法可以非常精确稳定地求解时域电场积分方程,即使是在时间迭代后期也不必采用任何求平均的过程;另外,该方法可以用于任意时间基函数并可以推广到高阶空间基函数的情形. 相似文献
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一种求解目标内谐振时散射截面的有效方法 总被引:2,自引:1,他引:1
众所周知,在内谐振频率点上,用矩量法求解电场或磁场表面积分方程将得到不正确的表面电流。文中应用奇异值分解和正交化方法对由电场积分方程计算出的表面电流进行修正,从而得到目标表面上产生散射场的真实电流分布。文中计算了一无限长理想导体圆柱内谐振时的散射截面,所得结果与解析解一致,并对一无限长理想导体正方柱的后向散射截面进行了计算,结果表明本文方法是有效和准确的。 相似文献
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时域阻抗矩阵元素的计算需要分别计算场单元和源单元上的空时积分,由于时间基函数的分域性以及时间基函数(如三角型时间基函数)导数的不连续性,使得采用高斯积分方法计算源单元上空时积分的计算精度较差且误差随着时间步长的减小而增大.本文通过将源单元上空时积分转变成为1D时间卷积分和1D空间解析积分来精确计算时域阻抗矩阵元素,并在此基础上利用时间步进算法求解了时域电场、磁场和混合场积分方程.通过计算实例表明该方法在较大的时间步长取值范围内均能确保时域积分方程时间步进算法求解的精度和后时稳定性. 相似文献
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We investigate the accuracy of the combined-field integral equation (CFIE) discretized with the Rao-Wilton-Glisson (RWG) basis functions for the solution of scattering and radiation problems involving three-dimensional conducting objects. Such a low-order discretization with the RWG functions renders the two components of CFIE, i.e., the electric-field integral equation (EFIE) and the magnetic-field integral equation (MFIE), incompatible, mainly because of the excessive discretization error of MFIE. Solutions obtained with CFIE are contaminated with the MFIE inaccuracy, and CFIE is also incompatible with EFIE and MFIE. We show that, in an iterative solution, the minimization of the residual error for CFIE involves a breakpoint, where a further reduction of the residual error does not improve the solution in terms of compatibility with EFIE, which provides a more accurate reference solution. This breakpoint corresponds to the last useful iteration, where the accuracy of CFIE is saturated and a further reduction of the residual error is practically unnecessary. 相似文献
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Direct solution of the EFIE with half the computation 总被引:1,自引:0,他引:1
When using the electric field integral equation (EFIE) with the same basis and testing functions, a complex symmetric (non-Hermitian) moment method matrix results. Stable methods that directly solved this matrix with roughly half the storage and execution time required for the nonsymmetric case exist. Apparently these methods are relatively unknown among moment method practitioners. Furthermore, the resulting advantage in storage and execution time of the EFIE (when a direct solution is used) over other methods (such as the MFIE and CFIE) seems not to be widely appreciated 相似文献
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利用图形处理单元(GPU)加速混合场积分方程(CFIE)分析导体目标电磁散射问题。较电场积分方程(EFIE)和磁场积分方程(MFIE),CFIE消除了内谐振问题,并且具有更好的条件数。求解的数值方法为基于 RWG基函数的矩量法(MoM)。所有计算步骤均在 GPU上实现,包括:阻抗元素填充、电压向量填充、矩阵方程的共轭梯度(CG)求解、雷达散射截面(RCS)计算。在保证数值精确度的前提下获得了数十倍的速度提升。 相似文献
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This paper describes the development of new vector boundary elements for solving electromagnetic (EM) scattering problems. The new elements are suitable for the magnetic field integral equation (MFIE), electrical field integral equation (EFIE), or the combination field integral equation (CFIE). The basis functions are assigned to the edges of an element, rather than to its nodes. The new element guarantees the continuity of the normal component of the surface current across element edges. Furthermore, the basis functions are hierarchical from linear to higher order, which enables one to use the new elements in a p-adaption scheme 相似文献
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Petre P. Swaminathan M. Veszely G. Sarkar T.K. 《Antennas and Propagation, IEEE Transactions on》1993,41(8):1069-1080
A set of integral equations based on the surface/surface formulation are developed for analyzing electromagnetic scattering by one-dimensional periodic structures. To compare the accuracy, efficiency, and robustness of the formulation, the electric field integral equation (EFIE), magnetic field integral equation (MFIE), and combined field integral equation (CFIE) are developed for analyzing the same structure for different excitations. Due to the periodicity of the structure, the integral equations are formulated in the spectral domain using the Fourier transform of the integrodifferential operators. The generalized-biconjugate-gradient-fast Fourier transform method with subdomain basis functions is used to solve the matrix equation 相似文献
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We present the linear-linear (LL) basis functions to improve the accuracy of the magnetic-field integral equation (MFIE) and the combined-field integral equation (CFIE) for three-dimensional electromagnetic scattering problems involving closed conductors. We consider the solutions of relatively large scattering problems by employing the multilevel fast multipole algorithm. Accuracy problems of MFIE and CFIE arising from their implementations with the conventional Rao-Wilton-Glisson (RWG) basis functions can be mitigated by using the LL functions for discretization. This is achieved without increasing the computational requirements and with only minor modifications in the existing codes based on the RWG functions 相似文献
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Donepudi K.C. Jian-Ming Jin Velamparambil S. Song J. Weng Cho Chew 《Antennas and Propagation, IEEE Transactions on》2001,49(7):1069-1078
A higher order multilevel fast multipole algorithm (MLFMA) is presented for solving integral equations of electromagnetic wave scattering by three-dimensional (3-D) conducting objects. This method employs higher order parametric elements to provide accurate modeling of the scatterer's geometry and higher order interpolatory vector basis functions for an accurate representation of the electric current density on the scatterer's surface. This higher order scheme leads to a significant reduction in the mesh density, thus the number of unknowns, without compromising the accuracy of geometry modeling. It is applied to the electric field integral equation (EFIE), the magnetic field integral equation (MFIE), and the combined field integral equation (CFIE), using Galerkin's testing approach. The resultant numerical system of equations is then solved using the MLFMA. Appropriate preconditioning techniques are employed to speedup the MLFMA solution. The proposed method is further implemented on distributed-memory parallel computers to harness the maximum power from presently available machines. Numerical examples are given to demonstrate the accuracy and efficiency of the method as well as the convergence of the higher order scheme 相似文献